The transformation of predentin to dentin takes place at a distinct site away from th periphery of odontoblasts and must be a finely controlled process. Biochemical, autoradiographic and morphologic data suggest that certain proteins made by odontoblasts are involved in this process. In order to gain further insight into the mechanisms of their involvement in dentinogenesis and mineralization, the biosynthesis and deposition of collagen, phosphoprotein and glycoproteins will be studied. These biochemical an autoradiographic studies will be performed with an odontoblast culture system developed in this laboratory. Simultaneously, further investigations on the biochemistry of collagen, phosphoprotein and glycoproteins found in dentin will be conducted.